tjh.dev
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1442907
3
927
Clone this repository
https://tangled.org/tjh.dev/kernel
https://tangled.org/did:plc:65gha4t3avpfpzmvpbwovss7/kernel
git@gordian.tjh.dev:tjh.dev/kernel
git@gordian.tjh.dev:did:plc:65gha4t3avpfpzmvpbwovss7/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
Both the vdso rework and the CONFIG_PAGE_SHIFT changes were merged during
the v6.9 merge window, so it is now possible to use CONFIG_PAGE_SHIFT
instead of including asm/page.h in the vdso.
This avoids the workaround for arm64 - commit 8b3843ae3634 ("vdso/datapage:
Quick fix - use asm/page-def.h for ARM64") and addresses a build warning
for powerpc64:
In file included from <built-in>:4:
In file included from /home/arnd/arm-soc/arm-soc/lib/vdso/gettimeofday.c:5:
In file included from ../include/vdso/datapage.h:25:
arch/powerpc/include/asm/page.h:230:9: error: result of comparison of constant 13835058055282163712 with expression of type 'unsigned long' is always true [-Werror,-Wtautological-constant-out-of-range-compare]
230 | return __pa(kaddr) >> PAGE_SHIFT;
| ^~~~~~~~~~~
arch/powerpc/include/asm/page.h:217:37: note: expanded from macro '__pa'
217 | VIRTUAL_WARN_ON((unsigned long)(x) < PAGE_OFFSET); \
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
arch/powerpc/include/asm/page.h:202:73: note: expanded from macro 'VIRTUAL_WARN_ON'
202 | #define VIRTUAL_WARN_ON(x) WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && (x))
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
arch/powerpc/include/asm/bug.h:88:25: note: expanded from macro 'WARN_ON'
88 | int __ret_warn_on = !!(x); \
| ^
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Link: https://lore.kernel.org/r/20240320180228.136371-1-arnd@kernel.org
Fix some text for consistency: s/lvl/level/ in a comment and use
correct/full function names in comments.
Correct spelling errors as reported by codespell.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240331172652.14086-7-rdunlap@infradead.org
Fix kernel-doc warnings in struct tick_sched:
tick-sched.h:103: warning: Function parameter or struct member 'idle_sleeptime_seq' not described in 'tick_sched'
tick-sched.h:104: warning: Excess struct member 'nohz_mode' description in 'tick_sched'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240331172652.14086-6-rdunlap@infradead.org
Fix a slew of kernel-doc warnings in tick-sched.c:
tick-sched.c:650: warning: Function parameter or struct member 'now' not described in 'tick_nohz_update_jiffies'
tick-sched.c:741: warning: No description found for return value of 'get_cpu_idle_time_us'
tick-sched.c:767: warning: No description found for return value of 'get_cpu_iowait_time_us'
tick-sched.c:1210: warning: No description found for return value of 'tick_nohz_idle_got_tick'
tick-sched.c:1228: warning: No description found for return value of 'tick_nohz_get_next_hrtimer'
tick-sched.c:1243: warning: No description found for return value of 'tick_nohz_get_sleep_length'
tick-sched.c:1282: warning: Function parameter or struct member 'cpu' not described in 'tick_nohz_get_idle_calls_cpu'
tick-sched.c:1282: warning: No description found for return value of 'tick_nohz_get_idle_calls_cpu'
tick-sched.c:1294: warning: No description found for return value of 'tick_nohz_get_idle_calls'
tick-sched.c:1577: warning: Function parameter or struct member 'hrtimer' not described in 'tick_setup_sched_timer'
tick-sched.c:1577: warning: Excess function parameter 'mode' description in 'tick_setup_sched_timer'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240331172652.14086-5-rdunlap@infradead.org
Fix kernel-doc format and warnings:
timer.h:26: warning: Cannot understand * @TIMER_DEFERRABLE: A deferrable timer will work normally when the on line 26 - I thought it was a doc line
timer.h:146: warning: No description found for return value of 'timer_pending'
timer.h:180: warning: No description found for return value of 'del_timer_sync'
timer.h:193: warning: No description found for return value of 'del_timer'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240331172652.14086-4-rdunlap@infradead.org
Fix punctuation, spellos, and kernel-doc warnings:
timekeeping.h:79: warning: No description found for return value of 'ktime_get_real'
timekeeping.h:95: warning: No description found for return value of 'ktime_get_boottime'
timekeeping.h:108: warning: No description found for return value of 'ktime_get_clocktai'
timekeeping.h:149: warning: Function parameter or struct member 'mono' not described in 'ktime_mono_to_real'
timekeeping.h:149: warning: No description found for return value of 'ktime_mono_to_real'
timekeeping.h:255: warning: Function parameter or struct member 'cs_id' not described in 'system_time_snapshot'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240331172652.14086-3-rdunlap@infradead.org
Fix kernel-doc warnings, text punctuation, and a kernel-doc marker
(change '%' to '&' to indicate a struct):
timecounter.h:72: warning: No description found for return value of 'cyclecounter_cyc2ns'
timecounter.h:85: warning: Function parameter or member 'tc' not described in 'timecounter_adjtime'
timecounter.h:111: warning: No description found for return value of 'timecounter_read'
timecounter.h:128: warning: No description found for return value of 'timecounter_cyc2time'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240331172652.14086-2-rdunlap@infradead.org
Pull Kbuild fixes from Masahiro Yamada:
- Deduplicate Kconfig entries for CONFIG_CXL_PMU
- Fix unselectable choice entry in MIPS Kconfig, and forbid this
structure
- Remove unused include/asm-generic/export.h
- Fix a NULL pointer dereference bug in modpost
- Enable -Woverride-init warning consistently with W=1
- Drop KCSAN flags from *.mod.c files
* tag 'kbuild-fixes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kconfig: Fix typo HEIGTH to HEIGHT
Documentation/llvm: Note s390 LLVM=1 support with LLVM 18.1.0 and newer
kbuild: Disable KCSAN for autogenerated *.mod.c intermediaries
kbuild: make -Woverride-init warnings more consistent
modpost: do not make find_tosym() return NULL
export.h: remove include/asm-generic/export.h
kconfig: do not reparent the menu inside a choice block
MIPS: move unselectable FIT_IMAGE_FDT_EPM5 out of the "System type" choice
cxl: remove CONFIG_CXL_PMU entry in drivers/cxl/Kconfig
Pull EDAC fixes from Borislav Petkov:
- Fix more issues in the AMD FMPM driver
* tag 'edac_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
RAS: Avoid build errors when CONFIG_DEBUG_FS=n
RAS/AMD/FMPM: Safely handle saved records of various sizes
RAS/AMD/FMPM: Avoid NULL ptr deref in get_saved_records()
Fixed a typo in some variables where height was misspelled as heigth.
Signed-off-by: Isak Ellmer <isak01@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull irq fixes from Borislav Petkov:
- Fix an unused function warning on irqchip/irq-armada-370-xp
- Fix the IRQ sharing with pinctrl-amd and ACPI OSL
* tag 'irq_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/armada-370-xp: Suppress unused-function warning
genirq: Introduce IRQF_COND_ONESHOT and use it in pinctrl-amd
A new helper was introduced for RAS modules to be able to get the RAS
subsystem debugfs root directory. The helper is defined in debugfs.c
which is only built when CONFIG_DEBUG_FS=y.
However, it's possible that the modules would include debugfs support
for optional functionality. One current example is the fmpm module. In
this case, a build error will occur when CONFIG_RAS_FMPM is selected and
CONFIG_DEBUG_FS=n.
Add an inline helper function stub for the CONFIG_DEBUG_FS=n case as the
fmpm module can function without the debugfs functionality too.
Fixes: 9d2b6fa09d15 ("RAS: Export helper to get ras_debugfs_dir")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218640
Reported-by: anthony s. knowles <akira.2020@protonmail.com>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: anthony s. knowles <akira.2020@protonmail.com>
Link: https://lore.kernel.org/r/20240325183755.776-1-bp@alien8.de
As of the first s390 pull request during the 6.9 merge window,
commit 691632f0e869 ("Merge tag 's390-6.9-1' of
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux"), s390 can be
built with LLVM=1 when using LLVM 18.1.0, which is the first version
that has SystemZ support implemented in ld.lld and llvm-objcopy.
Update the supported architectures table in the Kbuild LLVM
documentation to note this explicitly to make it more discoverable by
users and other developers. Additionally, this brings s390 in line with
the rest of the architectures in the table, which all support LLVM=1.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull x86 perf fixes from Borislav Petkov:
- Define the correct set of default hw events on AMD Zen4
- Use the correct stalled cycles PMCs on AMD Zen2 and newer
- Fix detection of the LBR freeze feature on AMD
* tag 'perf_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/amd/core: Define a proper ref-cycles event for Zen 4 and later
perf/x86/amd/core: Update and fix stalled-cycles-* events for Zen 2 and later
perf/x86/amd/lbr: Use freeze based on availability
x86/cpufeatures: Add new word for scattered features
README